Railway signaling



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I I o E# l .-1 4 -WZ 3 45 INVENTOR EaP .Allen HIS ATTORNEY Patented Mar. 4, 15941 'PATENT OFFICE RAILWAY sIoNALING Earl M. Allen, Swissvale, Pa., assigner to The Union Switch itr Signal Company, Swissvale, Pa., a corporation of Pennsylvania Application `luly 2li, 1940, Serial No. 347,241

,4 claims.

My invention relates to railway signaling, and particularly to signaling for the control of trahie movements along intersecting tracks.

A few features of my invention are the provision oi a locking relay for each track, a front contact of which is included in a clearing control circuit for each of the opposingk signals for its track, and a back contact of which is included y in a holding circuit for each of these signals; the HI locking relays are of a slow acting type to protect against quick changes in the selection of traffic movements; and protection against loss of shunt in an approach section is obtained by retaining a corresponding signal in the clear condition a l5' measured period of time after the loss of shunt occurs, and then preventing a conilicting signal from clearing until after the lapse of a further measured period of time.

The apparatus of my invention is an improvement over that disclosed in my copending application Serial No. 347,972, led July 27, 1940, for

Railway signaling.

I shall describe one form of apparatus embodying my invention, and shall then point out the novel features thereof in claims.

In the accompanying drawing, Fig. 1A is a diagrammatic View showing two intersecting railway tracks, and two signals for each track,y one on each side of the intersection, for governing traic movements in opposite directions'over the intersection; Fig. 1B is a diagrammatic view showing control circuits for a signal control relay for each of the signals; Fig. 1C is a diagrammatic View showing control circuits for two locking relays,

one for each track, and for a time element device for each of the locking relays; and Fig. 1D is a diagrammatic view showing circuits for controlling directional stick relays for one of the tracks.

Similar reference characters refer to similar parts in each of the views.

In each of the views, the contacts operated by the various relays or other devices are identified by numbers, such numbers having distinguishing prefixes from which they are separated by a dash when the contacts are shown apart from the relay or other device by which they are operated.

The prei-lx for each of these contact numbers comprises the reference character for the respective relay or other device by which the associated contacts are operated. For example, contact SHR-53 shown in the pick-up circuit for relay SSR in Fig. 1D is identified by the number 53 separated by a dash from the preX EHR which is the reference character for relay SHR bywhich g5 thisy contact is operated. Similarly, contact -TE- also shown in the circuits for relay ASSR, in Fig. 1D is identified by the number 55 separated by a dash from the prefix 3-4TE which is the reference character for the time element device by which this contact is operated. 5

Referring lirst to Fig. 1A, two intersecting railway tracks X and Z are shown, one of which, track X, is a high speed, heavy traic line, whereas-the other, track Z, is a low speed, light traflic line. Track X is divided by insulated joints 10 5 into sections AIT and A2T one of which, track section AIT, extends from the intersection of tracks X and Z in advance of signal I to a point in the rear of rsignal I, and the other of which, section AZT, extends from the intersection in 15 advance ofsignal 2 to a point in the rear of signal 2. Track Z is divided by insulated joints 5 into a detector section 3T extending through the intersection, an approach section AST adjacent one end of section 3T, and a second approach 20 section AfiT adjacent the opposite end of section 3T. A track battery 6 is connected across the rails adjacent one end of each section. A track relay, designated by the reference character R with a prefix comprising the reference char- 25 acter for the associated track section, is connected across the rails adjacent the opposite end of each section.I

Signals designated by the reference characters I and 2 are located adjacent track X for govern- 30 ing trac movementsin opposite directions on track X across the intersection of the two tracks. Signals designated by the reference characters 3 and liare placed adjacent the ends of track section '3T for governing trafc movements in 35 opposite directions on track Z across the intersection of the two tracks. As here shown, each of the signals is of the color light'type, but may be of any vother vsuitable design. As shown in the drawing, each of the signals I and 2 for track 40 X has a green or proceed lamp G and a red or stop lamp B., whereas each of the signals 3 and l for vtrack Z has a yellow or caution lamp Y and a vred or stop lamp R. Lighting circuits are sho-wn .for signals -I and 3. The lighting circuits for -sig- 45 nals 2 and i are similar to those shown for signals l and 3, respectively, and are therefore omitted from the drawing.

In Fig. 1B, pick-up and stick circuits are shown for slow release signal control relays IHR., ZHR, 50 `,3l-IR. and IHR for signalsl, 2, 3 and 4, respectively. Manually-controllable time element devices I ZTE and -3-'--lTE1 are shown which mayr beof the' well-knownclockwork type. These time element devices have contacts 32 and I9, respective- {2T-.5

.I for track Z.

ly, shown in the circuits for relays SHR and IHR which are closed only when the time element devices are in their normal or run down" vpositions. After being Wound up, time element device I-Z'IE closes a contact I-2TE-II, shown in a pick-up circuit for relay I-ZRGPSR in Fig. 1C, when the time element device has returned to within 20 seconds of its run down, position, which remains closed for 15 seconds,

opening seconds before the run down posi--` tion is reached. Time element device I-2TE also closes a contact I-ZTE-ZII in the pick-up circuit for relay IHR when the time element device is Within 5 seconds, for example, of the end of its operation upon returning to thenormal position. Similar contacts, designated similarly, are operated by time element device 3'4'IE.

In Fig, 1C, pick-up and stick circuits are shown for locking relay I-2RGPSR, for track As shown in the drawing, all parts are in their normal condition, that is, the track sections are unoccupied and hence the track relays arek energized; relays I-ZRGPSR and 3-4RGPSR are energized; relays IHR, ZHR, 3HR, 4I-IR, 3SR and GSR, and time element devices I2TER and S-ATER are deenergized; and the red lamps of all signals are lighted, and hence the signals are indicating stop.

Both a pick-up and a stick circuit are closed forenergizing relay I-ZRGPSR. The pick-up circuit which is closed passes from terminal B of a suitable source of current, through contacts ZI-IRf-, IHR- 8, A2TR-9, AITR-I0, and the winding of lrelay I-ZRGPSR to terminal C' of the same source ofv current. 'I'he stick circuit for this relay passes from terminal B, through contacts ZHR-'I and IHR-8, contact I3 of relay I-2RGPSR, and the winding of relay I-,'2RGPSR.to terminal C. Relay 3-4RGPSR is energized by similar pick-up and stick circuits.

The circuit by which lamp R of signal I is lighted passes from terminal B, through the back point of contact IHR-I4, and lamp R to terminal C. Lamps R of the other signals are lighted by similar circuits.

In describing in detail the operation of the apparatus shown in the accompanying drawing, I Yshall rst assume that, with all parts in the normal condition as just described, a train on track X, moving toward the right( as shown in the drawing, which I shall assume is the eastbound direction, enters section AIT, thereby deenergizing track relay AITR. Relay AITR, upon becoming deenergized, completes a pick-up circuit for relay IHR passing from terminal BY, through contact STR-I8, contact I9 of time element device 3-4TE, contacts I-2TE-20, 3--4TEfR-2I, 3-4RGPSR-22 and ATER-23, winding of relay IHR, front point of contact I-2RGPSR--24, and contact AITR-25 to terminal C. Relay IHR, upon becoming energized, opens its contact IHR-4i in the circuits previously traced for relay I-ZRGPSR, causing this V` through the front points of and I-'-2RGPSR'-I5, and lamp R to terminal C.

relay to become deenergized. Relay I-2RGPSR, upon becoming deenergized, completes a stick circuit for relay IHR which follows the path previously traced for the pick-up circuit :for relay IHR as far as the winding of relay IHR, and thence passing through the back point of contact I-2RGPSR-24, front point of contact IHR-26, and the back point of contact ZHR-ZI to terminal C',

Relay IHR, upon becoming energized While the front contacts of relay I-ZRGPSR are still closed, completes a second lighting circuit for lamp R of signal I passing from terminal B.

When relay I-ZRGPSR becomes deenergized in response to energization of relay IHR, the second lightingvcircuit for lamp R of signal I is opened and the lighting circuit for lamp G of this signal completed, passing from terminal B, through the frontpoint of contact IHR-I4, Iback point of contact I-2RGPSR-I5 and lamp G to terminal C. Signal I will then continue to display the proceed indication until the train enters section A2T, causing relay AZTR to open the circuit for relay IHR at its contact A2TR-23.

On account of relay A2'IR being deenergized, relay I-2RGPSR will not pick up until the train leaves track section A2T, and hence signal 2 will continue to display the stop indication.

As the train proceeds further and leaves section AZT, relay I--ZRGPSR Will become energized by its pick-up circuit previously traced. Relay I-ZRGPSR Will then complete its stick circuit previously traced. y

A front contact I--2RGPSR-35 is included contacts IHRf-I II in the circuits 'for relays SHR and 4HR, andv I shall next assume'that, with all parts again in the normal condition, an eastbound train enters section AIT and signal I again clears. Il

shall further assume that, a loss of shunt occurs While the train is in section AIT, permitting relay AAITR to become falsely energized. Relay IHR will then vremain energized for a time by its stick circuit previously traced, although its pick-up circuit is open at contact AITR- 25 due to the false energization of relay AITR.

With relay AITR falsely energized, time element device I-2TER will become energized by its circuit passing from-terminal B, through contacts A2TR-28 and AITR-29, contact 30 of relay I-ZRG-PSR, and time element device I-2IER to terminal C. If the loss of shunt in section AIT lasts long enough for time element device I-2TER to close its. iront contact I-2TER-3I, relay I-.-2RGPSR will become energized by a second pick-up circuit, passing from terminal B, through contacts A2TR-28, AITR-29 and I-2TER3I, and the winding of relay I2RGPSRv to terminal C. l

Relay I-2RGPSR,upon becoming energized, opens the stick circuit for relay IHR, vand if" relay AITR is still falsely energized, the pick-up circuit for relay IHR will be open and hence relay IHR will become deenergized, causing signal I to indicate stop. If, after the train has entered section AIT, a second train has entered section AST on track Z, signal 3 will not at once clear after signal I is controlled to indicate stop due to loss of shunt in section AIT, but Will be decuit will then be completed for relay 3SR which` layed in clearing until time element device I:-2TER cools off and permits its contact I-2TER-34 to close in the pick-up circuit for relay 3HR.

I shall again assume that all parts of the apparatus have been returned to the normal condition, and that. an eastbound train enters section AIT, causing signal I to clear. I shall further'assume that, after the train proceeds over the intersection and passes signal 2, it is desired that the train shall back up over the intersection without moving out of section AZT. Signal 2 will not clear, on account of relay I-ZRGPSR being deenergized.

In order to energize this relay, a trainman Will operate time element device I-ZTE to the reverse position, thereby opening all of the signal circuits. When this time element device runs down to within 2O seconds of its normalposition, relay I -ZRGPSR will become energizedby athird pick-up circuit, passing from terminal B, through contacts 2HR-"I, IHR-8 and I-ZTE--I I, and: the winding of relay I-ZRGPSR to terminal C. The stick circuit previously traced for relay I-ZRGPSR will then become closed.

When the release I-2TE runs down to within 5 seconds of its normal position, relay 2HR will become energized by its pick-up circuit which is similar to the pick-up circuit. previously traced for relay IHR, and which includes contact I-2TE--2il. Relay 2HR, upon becoming energized, will open the stick circuit for relay I-ZRGPSR thereby completing a stick circuit for relay 2HR which is similar to the stick circuit previously traced for relay IHR.

I shall assume'that all parts of the apparatus are again in the normal condition and that an eastbound train causesV signal I to clear, but that the train stops before passing signal I. If, noW, a train arrives on section A3T and if it is desired to let the second train on section A3T proceed over the intersection before the train on section AIT, a trainman will operate time element device 3-4TE to its reverse position, causing signal I to at once indicate stop on account of the opening of contact I 9 of device 3-4TE in the circuits for relay IHR. When release 3--4TE runs down to within 20 seconds of its normal position, relay I-ZRGPSR will become energized by a fourth pick-up circuit which is the same as the third pick-up circuit previously traced eX- cept including contact S-IITE-I 2 instead of contact I-ZTE-IL When release 3-4'IE continues on down to within 5 seconds of its normal position, relay SHR will become energized by its pick-up circuit including contact 3-4TE-33, and which is similar to the pick-up circuit previously traced for relay IHR. With relay 3HR energized, relay 3-4RGPSR will become deenergzed on account of its circuits being opened at contact SHR-42, causing signal 3 to display the yellow indication, The stick circuit for relay 3HR will then be completed through the back point of contact 3-4RGPSR-38, and which is similar4 to the stick circuit previously traced for relay IHR.

As the train proceeds and enters section 3T, relay 3TR will become deenergized, and its contact 3TR-I8 will then open the circuits for relay 3HE.. Relay SHR, however, is of the slow release type, and relay 3SR will therefore become energized by its pick-up circuit passing from terminal B, through contact 3TR-52, front point of contact 3HR-53, winding of relay SSR, and contact 3--4TE-55 to terminal C. A stick ciris the same as the pick-up circuit just traced. ex;- cept. including contact 54. of relay 3SR insteadv of the front point of contact 3ER- 53. With, rel-ay 3HR deenergized, signal 3 will be caused to indicateV stop. When the train enters section A4T,.

a second stick circuit will be completed for relay SSR passing from terminal. B, through contact ATR-, back point of contact 3HE- 53, contact 54 of relay 3SR, winding of relay 3SR and Contact 3-4TE-55 to terminal C.

With relay 3SR energized, 4a pick-up circuitl will be completed for relay 3-IIRGPSR as, soon as the train leaves section 3T, this pick-up circuit passing from terminal B, through contacts 3HR-li2, 4HR-43, A3TRf-45, SSR-48 and 3TR-5I, and the Winding of relay S-IIRGPSR to terminal C. With relay S-IIRGPSR again energized, signal I or signal Z can nowI clear for a train in section AIT or AZT, respectively, while the train on track Z occupies section AT.

I shall again assume that all parts of the apparatus are again in the normal condition, and that a train on section A3T causes signal 3 to clear. I shall further assume that while the train is on section 3T, after leaving section A3T and before entering section AIIT, a loss of shunt occurs, so that relay 3TR picks up falsely. Relay S-IRGPSR will then become energized by its pick-up circuit previously traced, and also by a second pick-up circuit which is the same as its pick-up circuit previously traced except including contact AfITR-Mi instead of contact 3SR-48, but on account of its being of the slow pick-up type it will not at once close its front contacts. If the loss of shunt in section 3T continues for a long enough time, relay SSR will release before relay 3-4RGPSR closes its front contacts.` If relay SSR releases before the train enters section AAT, and if relay 3--4RGPSR does not close its front contacts before the train enters section A4T, this relay cannot then become energized until the train on track Z leaves section A4T, andhence a train on track X cannot proceed over the intersection until after the train on track Z has p'assed clear through section A4T.

Although I have herein shown and described only one form of railway signaling embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and `scope of my invention.

Having thus described my invention, what I claim is:

1. Control apparatus for railway signaling for intersecting tracks in which two signals are provided for each track one on each side of the intersection for governing trai'lic movements in opposite directions over the intersection, comprising in combination, a signal relay for each of said signals, a locking relay for each of said tracks,

a clearing control circuit for energizing each of said signal relays including a front contact of each of said locking relays and a contact closed in response to a train arriving within a given distance in the rear of its signal, a stick circuit for retaining each of said signal relays energized including a front contact of its own and a back contact of the signal relay for the opposite signal as well as a back contact of the locking relay for its track and a front contact of the locking relay for the other track, energizing circuit means for each of said locking relays controlled by back contacts of the signal relays for the corresponddistance in the real1 of either signal for the corresponding track, and a clearing circuit for each signal vcontrolled by a front contact of its signal relay and by a back contact of the locking relay for its track.

. 2. Control apparatus for railway signaling lfor intersecting tracks in which two signals are-provided for each track one on each side of the in,

tersection for governing traffic movements in opposite directions over the intersection, comprising in combination, a locking relay for each of said tracks, a clearing control circuit for each of said signals controlled by a front contact of each of said locking relays and by a contact closed in response to a train arriving on its track Within a given distance in the rear of the corresponding signal, a holding circuit for each of said signals controlled by a back contact of the locking relay for its track and by a front contact of the locking relay for the other track for retaining the corresponding signal in the clear condition, and energizing circuit means for each of said locking relays controlled by contacts which are closed if the Signals for the corresponding track are indicating stop and also controlled by contacts which are closed only if there is no train on the corresponding track within a given distance in the rear of either signal for that track.

posite directions over the intersection comprising in combination, a locking relay for each of said tracks, energizing circuit means for each of said locking relays including contacts which are closed if the signals for the corresponding track are controlled ,to indicate stop, a time element device for each of said locking relays, an approach track section for each of said signals each provided with a track circuit including a track relay, an ener- :escasasL gizing circuit for each of said time element detrack, an auxiliary energizing circuit for each of said locking relays controlled'by front contacts of the approach track section relays for the corresponding track and by a contact'closed by its time element device after its time element device has been energized. a measured period of time, a clearing control circuit for each of said signals controlled by a front contact of each of said locking relays and by a back contact of its approach track section relay, and a holding circuit for each of said signals controlled by a back contact of the locking relay for its track and by a front contact of the locking relay for the other track for retaining the corresponding signal in the clear condition.

4. Control apparatus for railway signaling for intersecting tracks in which two signals are provided for each track one on each side of the intersection for governing traffic movements in opposite directions over the intersection, comprising in combination, a locking relay of the slow acting type for each of said tracks, a clearing control circuit for each of said signals controlled by a front contact of each of said locking relays and by a contact closed in response to a train on its track within a given distance in the rear of the corresponding signal, a holding circuit for each vof said signals controlled by a back Contact of the locking relay for its track and by a front contact of the locking relay for the other track for retaining the corresponding signal in the clear condition, and energizing circuit means for each of said locking relays controlled by contacts which are closed if the signals for the corresponding track are indicating stop and if there is no train on the corresponding track between the signals for that track.

EARL M. ALLEN. 

